git-svn-id: svn://svn.jdownloader.org/jdownloader/trunk@37 ebf7c1c2-ba36-0410-9fe8-c592906822b4

jd/captcha/GifDecoder.java

@@ -0,0 +1,819 @@
+package jd.captcha;
+
+import java.awt.AlphaComposite;
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Graphics2D;
+import java.awt.Rectangle;
+import java.awt.image.BufferedImage;
+import java.awt.image.DataBufferInt;
+import java.io.BufferedInputStream;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.util.ArrayList;
+
+/**
+ * Form:http://www.java2s.com/Code/Java/2D-Graphics-GUI/GiffileEncoder.htm
+ * Class GifDecoder - Decodes a GIF file into one or more frames. <br>
+ * 
+ * <pre>
+ *  Example:
+ *     GifDecoder d = new GifDecoder();
+ *     d.read(&quot;sample.gif&quot;);
+ *     int n = d.getFrameCount();
+ *     for (int i = 0; i &lt; n; i++) {
+ *        BufferedImage frame = d.getFrame(i);  // frame i
+ *        int t = d.getDelay(i);  // display duration of frame in milliseconds
+ *        // do something with frame
+ *     }
+ * </pre>
+ * 
+ * No copyright asserted on the source code of this class. May be used for any
+ * purpose, however, refer to the Unisys LZW patent for any additional
+ * restrictions. Please forward any corrections to kweiner@fmsware.com.
+ * 
+ * @author Kevin Weiner, FM Software; LZW decoder adapted from John Cristy's
+ *         ImageMagick.
+ * @version 1.03 November 2003
+ * 
+ */
+
+public class GifDecoder {
+
+  /**
+   * File read status: No errors.
+   */
+  public static final int STATUS_OK = 0;
+
+  /**
+   * File read status: Error decoding file (may be partially decoded)
+   */
+  public static final int STATUS_FORMAT_ERROR = 1;
+
+  /**
+   * File read status: Unable to open source.
+   */
+  public static final int STATUS_OPEN_ERROR = 2;
+
+  protected BufferedInputStream in;
+
+  protected int status;
+
+  protected int width; // full image width
+
+  protected int height; // full image height
+
+  protected boolean gctFlag; // global color table used
+
+  protected int gctSize; // size of global color table
+
+  protected int loopCount = 1; // iterations; 0 = repeat forever
+
+  protected int[] gct; // global color table
+
+  protected int[] lct; // local color table
+
+  protected int[] act; // active color table
+
+  protected int bgIndex; // background color index
+
+  protected int bgColor; // background color
+
+  protected int lastBgColor; // previous bg color
+
+  protected int pixelAspect; // pixel aspect ratio
+
+  protected boolean lctFlag; // local color table flag
+
+  protected boolean interlace; // interlace flag
+
+  protected int lctSize; // local color table size
+
+  protected int ix, iy, iw, ih; // current image rectangle
+
+  protected Rectangle lastRect; // last image rect
+
+  protected BufferedImage image; // current frame
+
+  protected BufferedImage lastImage; // previous frame
+
+  protected byte[] block = new byte[256]; // current data block
+
+  protected int blockSize = 0; // block size
+
+  // last graphic control extension info
+  protected int dispose = 0;
+
+  // 0=no action; 1=leave in place; 2=restore to bg; 3=restore to prev
+  protected int lastDispose = 0;
+
+  protected boolean transparency = false; // use transparent color
+
+  protected int delay = 0; // delay in milliseconds
+
+  protected int transIndex; // transparent color index
+
+  protected static final int MaxStackSize = 4096;
+
+  // max decoder pixel stack size
+
+  // LZW decoder working arrays
+  protected short[] prefix;
+
+  protected byte[] suffix;
+
+  protected byte[] pixelStack;
+
+  protected byte[] pixels;
+
+  protected ArrayList frames; // frames read from current file
+
+  protected int frameCount;
+
+  static class GifFrame {
+    /**
+     * @param im
+     * @param del
+     */
+    public GifFrame(BufferedImage im, int del) {
+      image = im;
+      delay = del;
+    }
+
+    /**
+     * 
+     */
+    public BufferedImage image;
+
+    /**
+     * 
+     */
+    public int delay;
+  }
+
+  /**
+   * Gets display duration for specified frame.
+   * 
+   * @param n
+   *          int index of frame
+   * @return delay in milliseconds
+   */
+  public int getDelay(int n) {
+    //
+    delay = -1;
+    if ((n >= 0) && (n < frameCount)) {
+      delay = ((GifFrame) frames.get(n)).delay;
+    }
+    return delay;
+  }
+
+  /**
+   * Gets the number of frames read from file.
+   * 
+   * @return frame count
+   */
+  public int getFrameCount() {
+    return frameCount;
+  }
+
+  /**
+   * Gets the first (or only) image read.
+   * 
+   * @return BufferedImage containing first frame, or null if none.
+   */
+  public BufferedImage getImage() {
+    return getFrame(0);
+  }
+
+  /**
+   * Gets the "Netscape" iteration count, if any. A count of 0 means repeat
+   * indefinitiely.
+   * 
+   * @return iteration count if one was specified, else 1.
+   */
+  public int getLoopCount() {
+    return loopCount;
+  }
+
+  /**
+   * Creates new frame image from current data (and previous frames as specified
+   * by their disposition codes).
+   */
+  protected void setPixels() {
+    // expose destination image's pixels as int array
+    int[] dest = ((DataBufferInt) image.getRaster().getDataBuffer()).getData();
+
+    // fill in starting image contents based on last image's dispose code
+    if (lastDispose > 0) {
+      if (lastDispose == 3) {
+        // use image before last
+        int n = frameCount - 2;
+        if (n > 0) {
+          lastImage = getFrame(n - 1);
+        } else {
+          lastImage = null;
+        }
+      }
+
+      if (lastImage != null) {
+        int[] prev = ((DataBufferInt) lastImage.getRaster().getDataBuffer()).getData();
+        System.arraycopy(prev, 0, dest, 0, width * height);
+        // copy pixels
+
+        if (lastDispose == 2) {
+          // fill last image rect area with background color
+          Graphics2D g = image.createGraphics();
+          Color c = null;
+          if (transparency) {
+            c = new Color(0, 0, 0, 0); // assume background is transparent
+          } else {
+            c = new Color(lastBgColor); // use given background color
+          }
+          g.setColor(c);
+          g.setComposite(AlphaComposite.Src); // replace area
+          g.fill(lastRect);
+          g.dispose();
+        }
+      }
+    }
+
+    // copy each source line to the appropriate place in the destination
+    int pass = 1;
+    int inc = 8;
+    int iline = 0;
+    for (int i = 0; i < ih; i++) {
+      int line = i;
+      if (interlace) {
+        if (iline >= ih) {
+          pass++;
+          switch (pass) {
+          case 2:
+            iline = 4;
+            break;
+          case 3:
+            iline = 2;
+            inc = 4;
+            break;
+          case 4:
+            iline = 1;
+            inc = 2;
+          }
+        }
+        line = iline;
+        iline += inc;
+      }
+      line += iy;
+      if (line < height) {
+        int k = line * width;
+        int dx = k + ix; // start of line in dest
+        int dlim = dx + iw; // end of dest line
+        if ((k + width) < dlim) {
+          dlim = k + width; // past dest edge
+        }
+        int sx = i * iw; // start of line in source
+        while (dx < dlim) {
+          // map color and insert in destination
+          int index = ((int) pixels[sx++]) & 0xff;
+          int c = act[index];
+          if (c != 0) {
+            dest[dx] = c;
+          }
+          dx++;
+        }
+      }
+    }
+  }
+
+  /**
+   * Gets the image contents of frame n.
+ * @param n 
+   * 
+   * @return BufferedImage representation of frame, or null if n is invalid.
+   */
+  public BufferedImage getFrame(int n) {
+    BufferedImage im = null;
+    if ((n >= 0) && (n < frameCount)) {
+      im = ((GifFrame) frames.get(n)).image;
+    }
+    return im;
+  }
+
+  /**
+   * Gets image size.
+   * 
+   * @return GIF image dimensions
+   */
+  public Dimension getFrameSize() {
+    return new Dimension(width, height);
+  }
+
+  /**
+   * Reads GIF image from stream
+   * 
+   * @param is
+   *          containing GIF file.
+   * @return read status code (0 = no errors)
+   */
+  public int read(BufferedInputStream is) {
+    init();
+    if (is != null) {
+      in = is;
+      readHeader();
+      if (!err()) {
+        readContents();
+        if (frameCount < 0) {
+          status = STATUS_FORMAT_ERROR;
+        }
+      }
+    } else {
+      status = STATUS_OPEN_ERROR;
+    }
+    try {
+      is.close();
+    } catch (IOException e) {
+    }
+    return status;
+  }
+
+  /**
+   * Reads GIF image from stream
+   * 
+   * @param is
+   *          containing GIF file.
+   * @return read status code (0 = no errors)
+   */
+  public int read(InputStream is) {
+    init();
+    if (is != null) {
+      if (!(is instanceof BufferedInputStream))
+        is = new BufferedInputStream(is);
+      in = (BufferedInputStream) is;
+      readHeader();
+      if (!err()) {
+        readContents();
+        if (frameCount < 0) {
+          status = STATUS_FORMAT_ERROR;
+        }
+      }
+    } else {
+      status = STATUS_OPEN_ERROR;
+    }
+    try {
+      is.close();
+    } catch (IOException e) {
+    }
+    return status;
+  }
+
+  /**
+   * Reads GIF file from specified file/URL source (URL assumed if name contains
+   * ":/" or "file:")
+   * 
+   * @param name
+   *          String containing source
+   * @return read status code (0 = no errors)
+   */
+  public int read(String name) {
+    status = STATUS_OK;
+    try {
+      name = name.trim().toLowerCase();
+      if ((name.indexOf("file:") >= 0) || (name.indexOf(":/") > 0)) {
+        URL url = new URL(name);
+        in = new BufferedInputStream(url.openStream());
+      } else {
+        in = new BufferedInputStream(new FileInputStream(name));
+      }
+      status = read(in);
+    } catch (IOException e) {
+      status = STATUS_OPEN_ERROR;
+    }
+
+    return status;
+  }
+
+  /**
+   * Decodes LZW image data into pixel array. Adapted from John Cristy's
+   * ImageMagick.
+   */
+  protected void decodeImageData() {
+    int NullCode = -1;
+    int npix = iw * ih;
+    int available, clear, code_mask, code_size, end_of_information, in_code, old_code, bits, code, count, i, datum, data_size, first, top, bi, pi;
+
+    if ((pixels == null) || (pixels.length < npix)) {
+      pixels = new byte[npix]; // allocate new pixel array
+    }
+    if (prefix == null)
+      prefix = new short[MaxStackSize];
+    if (suffix == null)
+      suffix = new byte[MaxStackSize];
+    if (pixelStack == null)
+      pixelStack = new byte[MaxStackSize + 1];
+
+    // Initialize GIF data stream decoder.
+
+    data_size = read();
+    clear = 1 << data_size;
+    end_of_information = clear + 1;
+    available = clear + 2;
+    old_code = NullCode;
+    code_size = data_size + 1;
+    code_mask = (1 << code_size) - 1;
+    for (code = 0; code < clear; code++) {
+      prefix[code] = 0;
+      suffix[code] = (byte) code;
+    }
+
+    // Decode GIF pixel stream.
+
+    datum = bits = count = first = top = pi = bi = 0;
+
+    for (i = 0; i < npix;) {
+      if (top == 0) {
+        if (bits < code_size) {
+          // Load bytes until there are enough bits for a code.
+          if (count == 0) {
+            // Read a new data block.
+            count = readBlock();
+            if (count <= 0)
+              break;
+            bi = 0;
+          }
+          datum += (((int) block[bi]) & 0xff) << bits;
+          bits += 8;
+          bi++;
+          count--;
+          continue;
+        }
+
+        // Get the next code.
+
+        code = datum & code_mask;
+        datum >>= code_size;
+        bits -= code_size;
+
+        // Interpret the code
+
+        if ((code > available) || (code == end_of_information))
+          break;
+        if (code == clear) {
+          // Reset decoder.
+          code_size = data_size + 1;
+          code_mask = (1 << code_size) - 1;
+          available = clear + 2;
+          old_code = NullCode;
+          continue;
+        }
+        if (old_code == NullCode) {
+          pixelStack[top++] = suffix[code];
+          old_code = code;
+          first = code;
+          continue;
+        }
+        in_code = code;
+        if (code == available) {
+          pixelStack[top++] = (byte) first;
+          code = old_code;
+        }
+        while (code > clear) {
+          pixelStack[top++] = suffix[code];
+          code = prefix[code];
+        }
+        first = ((int) suffix[code]) & 0xff;
+
+        // Add a new string to the string table,
+
+        if (available >= MaxStackSize)
+          break;
+        pixelStack[top++] = (byte) first;
+        prefix[available] = (short) old_code;
+        suffix[available] = (byte) first;
+        available++;
+        if (((available & code_mask) == 0) && (available < MaxStackSize)) {
+          code_size++;
+          code_mask += available;
+        }
+        old_code = in_code;
+      }
+
+      // Pop a pixel off the pixel stack.
+
+      top--;
+      pixels[pi++] = pixelStack[top];
+      i++;
+    }
+
+    for (i = pi; i < npix; i++) {
+      pixels[i] = 0; // clear missing pixels
+    }
+
+  }
+
+  /**
+   * Returns true if an error was encountered during reading/decoding
+   */
+  protected boolean err() {
+    return status != STATUS_OK;
+  }
+
+  /**
+   * Initializes or re-initializes reader
+   */
+  protected void init() {
+    status = STATUS_OK;
+    frameCount = 0;
+    frames = new ArrayList();
+    gct = null;
+    lct = null;
+  }
+
+  /**
+   * Reads a single byte from the input stream.
+   */
+  protected int read() {
+    int curByte = 0;
+    try {
+      curByte = in.read();
+    } catch (IOException e) {
+      status = STATUS_FORMAT_ERROR;
+    }
+    return curByte;
+  }
+
+  /**
+   * Reads next variable length block from input.
+   * 
+   * @return number of bytes stored in "buffer"
+   */
+  protected int readBlock() {
+    blockSize = read();
+    int n = 0;
+    if (blockSize > 0) {
+      try {
+        int count = 0;
+        while (n < blockSize) {
+          count = in.read(block, n, blockSize - n);
+          if (count == -1)
+            break;
+          n += count;
+        }
+      } catch (IOException e) {
+      }
+
+      if (n < blockSize) {
+        status = STATUS_FORMAT_ERROR;
+      }
+    }
+    return n;
+  }
+
+  /**
+   * Reads color table as 256 RGB integer values
+   * 
+   * @param ncolors
+   *          int number of colors to read
+   * @return int array containing 256 colors (packed ARGB with full alpha)
+   */
+  protected int[] readColorTable(int ncolors) {
+    int nbytes = 3 * ncolors;
+    int[] tab = null;
+    byte[] c = new byte[nbytes];
+    int n = 0;
+    try {
+      n = in.read(c);
+    } catch (IOException e) {
+    }
+    if (n < nbytes) {
+      status = STATUS_FORMAT_ERROR;
+    } else {
+      tab = new int[256]; // max size to avoid bounds checks
+      int i = 0;
+      int j = 0;
+      while (i < ncolors) {
+        int r = ((int) c[j++]) & 0xff;
+        int g = ((int) c[j++]) & 0xff;
+        int b = ((int) c[j++]) & 0xff;
+        tab[i++] = 0xff000000 | (r << 16) | (g << 8) | b;
+      }
+    }
+    return tab;
+  }
+
+  /**
+   * Main file parser. Reads GIF content blocks.
+   */
+  protected void readContents() {
+    // read GIF file content blocks
+    boolean done = false;
+    while (!(done || err())) {
+      int code = read();
+      switch (code) {
+
+      case 0x2C: // image separator
+        readImage();
+        break;
+
+      case 0x21: // extension
+        code = read();
+        switch (code) {
+        case 0xf9: // graphics control extension
+          readGraphicControlExt();
+          break;
+
+        case 0xff: // application extension
+          readBlock();
+          String app = "";
+          for (int i = 0; i < 11; i++) {
+            app += (char) block[i];
+          }
+          if (app.equals("NETSCAPE2.0")) {
+            readNetscapeExt();
+          } else
+            skip(); // don't care
+          break;
+
+        default: // uninteresting extension
+          skip();
+        }
+        break;
+
+      case 0x3b: // terminator
+        done = true;
+        break;
+
+      case 0x00: // bad byte, but keep going and see what happens
+        break;
+
+      default:
+        status = STATUS_FORMAT_ERROR;
+      }
+    }
+  }
+
+  /**
+   * Reads Graphics Control Extension values
+   */
+  protected void readGraphicControlExt() {
+    read(); // block size
+    int packed = read(); // packed fields
+    dispose = (packed & 0x1c) >> 2; // disposal method
+    if (dispose == 0) {
+      dispose = 1; // elect to keep old image if discretionary
+    }
+    transparency = (packed & 1) != 0;
+    delay = readShort() * 10; // delay in milliseconds
+    transIndex = read(); // transparent color index
+    read(); // block terminator
+  }
+
+  /**
+   * Reads GIF file header information.
+   */
+  protected void readHeader() {
+    String id = "";
+    for (int i = 0; i < 6; i++) {
+      id += (char) read();
+    }
+    if (!id.startsWith("GIF")) {
+      status = STATUS_FORMAT_ERROR;
+      return;
+    }
+
+    readLSD();
+    if (gctFlag && !err()) {
+      gct = readColorTable(gctSize);
+      bgColor = gct[bgIndex];
+    }
+  }
+
+  /**
+   * Reads next frame image
+   */
+  @SuppressWarnings("unchecked")
+protected void readImage() {
+    ix = readShort(); // (sub)image position & size
+    iy = readShort();
+    iw = readShort();
+    ih = readShort();
+
+    int packed = read();
+    lctFlag = (packed & 0x80) != 0; // 1 - local color table flag
+    interlace = (packed & 0x40) != 0; // 2 - interlace flag
+    // 3 - sort flag
+    // 4-5 - reserved
+    lctSize = 2 << (packed & 7); // 6-8 - local color table size
+
+    if (lctFlag) {
+      lct = readColorTable(lctSize); // read table
+      act = lct; // make local table active
+    } else {
+      act = gct; // make global table active
+      if (bgIndex == transIndex)
+        bgColor = 0;
+    }
+    int save = 0;
+    if (transparency) {
+      save = act[transIndex];
+      act[transIndex] = 0; // set transparent color if specified
+    }
+
+    if (act == null) {
+      status = STATUS_FORMAT_ERROR; // no color table defined
+    }
+
+    if (err())
+      return;
+
+    decodeImageData(); // decode pixel data
+    skip();
+
+    if (err())
+      return;
+
+    frameCount++;
+
+    // create new image to receive frame data
+    image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB_PRE);
+
+    setPixels(); // transfer pixel data to image
+
+    frames.add(new GifFrame(image, delay)); // add image to frame list
+
+    if (transparency) {
+      act[transIndex] = save;
+    }
+    resetFrame();
+
+  }
+
+  /**
+   * Reads Logical Screen Descriptor
+   */
+  protected void readLSD() {
+
+    // logical screen size
+    width = readShort();
+    height = readShort();
+
+    // packed fields
+    int packed = read();
+    gctFlag = (packed & 0x80) != 0; // 1 : global color table flag
+    // 2-4 : color resolution
+    // 5 : gct sort flag
+    gctSize = 2 << (packed & 7); // 6-8 : gct size
+
+    bgIndex = read(); // background color index
+    pixelAspect = read(); // pixel aspect ratio
+  }
+
+  /**
+   * Reads Netscape extenstion to obtain iteration count
+   */
+  protected void readNetscapeExt() {
+    do {
+      readBlock();
+      if (block[0] == 1) {
+        // loop count sub-block
+        int b1 = ((int) block[1]) & 0xff;
+        int b2 = ((int) block[2]) & 0xff;
+        loopCount = (b2 << 8) | b1;
+      }
+    } while ((blockSize > 0) && !err());
+  }
+
+  /**
+   * Reads next 16-bit value, LSB first
+   */
+  protected int readShort() {
+    // read 16-bit value, LSB first
+    return read() | (read() << 8);
+  }
+
+  /**
+   * Resets frame state for reading next image.
+   */
+  protected void resetFrame() {
+    lastDispose = dispose;
+    lastRect = new Rectangle(ix, iy, iw, ih);
+    lastImage = image;
+    lastBgColor = bgColor;
+    @SuppressWarnings("unused")
+    int dispose = 0;
+    @SuppressWarnings("unused")
+    boolean transparency = false;
+    @SuppressWarnings("unused")
+    int delay = 0;
+    lct = null;
+  }
+
+  /**
+   * Skips variable length blocks up to and including next zero length block.
+   */
+  protected void skip() {
+    do {
+      readBlock();
+    } while ((blockSize > 0) && !err());
+  }
+}